Air conditioning apparatus



5 Sheets-Sheet 1 T. W. CARRAWAY AIR CONDITIONING APPARATUS Filed NOV.30, 1944 March 16, 1948.

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AIR CONDITIONING APPARATUS Filed Nov. 30, 1944 5 Sheets-Sheet 5 Figa.

Thomas Carrawa/y w# MMY u Patented Mar. 16, 1948 UNITED STATES PATENTOFFICE AIR CONDITIONING APPARATUS Thomas W. Carraway, Dallas, Tex.Application November 30, 1944, Serial No. 565,839

'i Claims.

This invention relates to air conditioning apparatus and moreparticularly to apparatus for washing air to remove entrained foreignparticles and dust and for cooling the air by evapora- Ation of thecleaning or washing liquid.

Apparatus of this general class heretofore known has had numerousdisadvantages. Elective cleaning of air by Washing requires the use ofgreat quantities of washing liquid, e. g., water, which, if notrecirculated, is very expansive. In prior installations in which thewashing water is recirculated it has not been possible to maintain thefilters clean and consequently their eflciency has fallen rapidly,requiring frequent shut-downs for filter replacement.

An object of the present invention is to provide a new and improvedapparatus of the class referred to in which the filter, e. g., a mat orpack of glass strands or the like, is constantly and copiously bathed inan economical, way with cleaning liquid which, during the course ofbeing recirculated, drains through the filter andA car-I ries off thesolid particles.

Another object of the invention is to provide improved equipment forcreating, in an-air conditioning duct or chamber, a diiused volume orbody of cleaning liquid varying from relatively coarse separatedparticles tofinely atomized liquid constituting a mist or fog throughwhich the air must pass before owing through a filter.

A further object of the invention is to provide improved automaticcontrols for apparatus' of the character stated. Other objects willbecome apparent from a reading of the following description, theappended claims, and the accompanying drawings, in which:

Figure 1 is a longitudinal vertical section of' air conditioningapparatus embodying the invention, some parts being shownin elevation;

Figure 2 is a horizontal section on the line 2--2 of Figure 1;

Figure 3 is an end elevation showing the apparatus as viewed from theleft of Figure 1 with parts of an entrance screen and louvers or vanesbeing broken away in order thattinterior parts may be seen, someexternal appurtenances also being omitted;

Figure 4 is a fragmentary longitudinal vertical section of the entranceend portion of the air conditioning apparatus drawn on an enlargedscale;

Figure 5 is a fragmentary vertical section on the line 5--5 of Figure 4drawn on an enlarged scale;

Figure 6 is an-enlarged fragmentary plan view of equipment for addingmake-up evaporative iiuid to a main fluid tank;

Figure 7 is -a detail view partly in section on the line '1 -1 of Figure6, and partly in eleva- 5 tion showing a'valve for controlling theadding Y of make-up evaporative uid:

Figure 8 is a wiring diagram showing a control circuit.

'I'he illustrative embodiment of air washing or conditioning apparatusembodying the invention includes a casing or duct A and conventionalequipment including a `blower B for moving air through the casing forbeing conditioned. 'I'he blower B is mounted on a bracket or frame l andis driven through a belt 2 by an electric motor 3 supported on a bracket4. The blower shown is of the well known squirrel cage centrifugal typeand its structural details are not illustrated. When the blower isrunning air enters the duct A in'the direction of the arrow 5 in Figure1, passes through'the duct A to the center of the blower, and is thenrdischarged from the blower as indicated by the arrow 6. Thus, iiow ofair through the casing or duct A is from left: to right as viewed inFigures 1, 2 and 4.

The air owing through the duct A rst passes through a. wire mesh screen'l which prevents entrained leaves, large insects or other sizableparticles or objects from entering the duct. 'Ihe air then impinges uponand passes between louvers or vanes 8, the purpose of which will bedescribed later, and ows on to a washing and conditioning chamber 9inthe bottom of which'is mounted liquid throwing and atomizing equipmentgenerally designated l0. The right hand end of the conditioning andwashing chamber 9 is bounded by a first lter or aeration pack Il mountedin the duct to extend across or transversely to the iiow of air. Afterleaving the irst 'filter Il the t 40 air stream passes through an openspace I 2 and then through a second filter or aeration pack I3, andnally to the chamber I4 in which the blower B is mounted.

In accordance with one feature of the invention the liquid throwing andatomizing equipment I0 is of novel construction, has new andadvantageous operating advantages, and is so coordinated or related tothe louvers 8 and the filter or aeration pack equipment as to providefor more effective conditioning of the air, particularly its washing orcleaning, than heretofore has been possible. One of theadvantageousoper- ,ating features resides in the production in thechamber 9 of a diiused volume o-f washing liquid which varies fromrelatively coarse particles in the region of the filter II to very nnelydivided or atomized particles constituting a mist or fog in the regionof the vanes e. The coarsely separated or diffused particles in theregion of the filter Il are thrown against the latter in a compact heavystream directed mainly against the top portion of the filter so asforcibly to dislodge from the filter deposited particles of dust, dirt.or foreign matter which have been removed from the air stream.Preferably the filter I I comprises a mat or pack of glass strands orfibers Iln supported by wire mesh screens I Ib, although other materialhaving substantially the properties of glass strands or fibers may beused. The second lter pack I3 may ble of similar construction includinga mat or pack of glass or the like strands or fibers I3n supported byscreens I3?.

The cleaning liquid thrown upon the upper portion of the lter IItrickles or runs down through the lower portions of the filter and picksup and carries with it foreign matter which has been deposited. Theliquid and the foreign matter then drops into a tank I 5 which formsthev bottom of the casing A. Preferably the illters I I and I 3 aresupported on a stand I 6 formed with openings I1 permitting the drainageof the liquid from the filters.

The liquid throwing and atomizing equipment.

III is itself of such construction and is so related to the filter IIand vanes 8 as to effect highly efiicient cleaning and conditioning ofthe air at a cost much lower than has been possible with the use oi highpressure pumps and high pressure atomizing nozzles as heretoforepracticed. The improved liquid throwing and atomizing equipment shownfor the purposes of illustration in,- cluries a horizontal shaft I8 inthe bottom of the duct A extending across or transversely to thedirection of flow of air. The shaft is journaled in bearings I9supported at the ends of parallel channel irons 20 resting upon rubbervibration absorbing cushioning elements 2i which in turn are supportedupon angle members 22 resting upon the bottom of the tank I 5. Spaced ordeployed alone.r and fixed to the shafti8 is a plurality of discs 23which are disposed respectively in planes parallel to the direction ofair flow in advance of the filter I I. Closely embracing the lowerportion of each disc with operating clearance is a pan 24 supported bybrackets 25 carried on the channel members 20. Each individual pan isformed with openings 26 in its lower portion below the normal level ofevaporative cleaning liquid in the bottom tank I5.

In operation the shaft is rotated in the direction of the arrow 21 inFigure 4 by a motor 2,8 connected tothe shaft by a flexible coupling 29,the arrangement being such that the lower portions of the discs 23 runthrough the supplies of liquid in the individual pans 24 and theperipheries of the discs leave or move out ofthe pans upwardly adjacentthe filter II. The cleaning liquid adhering to the discs is thus thrownupwardly in a relatively coarse stream or succession of separatedparticles directed against the top portion of the filter II by the edges30 of the pans which act as deilectors, preventing a substantial amountof the cleaning liquid from being thrown directly against the lowerportion of the filter II. The liquid drains down through the filter insufliclent amount to maintain the lower. part of the filter wet, andconsequently direction of the stream upon the top portion of the ltergives the desirable result of substantial uniformity of wetness andwashing effect throughout the whole filter.

The liquid drains down through the filter, over the face of the filter.and the in-rush of air caused by the blower covers the face andsaturates aeration pack II with the small particles of fluid dischargedfrom the discs which envelops the myriad fibers in the aeration pack andthis increases the saturation efllciency and improves evaporation. Theimpact of the fluid particles on the face of aeration pack I I has anadditional advantage of thoroughly cleansing the filter of suspendedmatter that is washedfrom the face and fibers of aeration pack II intopan I5.

Most effective removal of foreign matter from the air and cooling of airpassing through the duct A is obtained by subjecting the air topreliminary treatment by moisture before the air passes through thefilter II. In accordance with the invention the treating of the air inthis man ner is made possible by so constructing and arranging theequipment i0 that liquid picked up in the pans 24 is thrown off flrst ina relatively coarse series of streams or sheets of liquid particles inthe region of the filter II and in progressively more finely separatedor atomized condition throughout'the chamber 9 from right to left asviewed in Figure 4, the condition of the moisture in the region of thelouvers 8 being such as to constitute substantially a mist or fog.

I have found that this desirable result can be produced by forming thediscs 23 in such manner that some of the liquid they pick up in the pans24 is thrown ofi from the disc peripheries immediately upon emergingfrom the pans 24 while additional liquid picked up in the pans isretarded in being thrown oi from the discs 23 so as to be thrown o f indecreasing amounts as the disc peripheral portions move counterclockwiseas viewed in Figure 4 from right to left above the pans 24. In theillustrative construction each disc 23 is formed with a concentric facegroove 3| adjacent the disc periphery and preferably thrown offcentrifugally in relatively coarsely separated condition adjacent thefilter II. -The remainder of the liquid carried on the disc peripherlesis thrown oi in progressively decreasing amounts and inI increasingdegree of separation or atomization. Liquid contained in the grooves 3lhas to work its way laterally to the faces of the discs before it can bethrown oil.

Thus, some of the groove-held liquid is not discharged irom the discsuntil they have moved through substantially degrees after leaving theliquid baths. Consequently, cleaning liquid is diffused throughoutsubstantially the whole of the chamber 9 Without the use of expensivehigh pressure pump and nozzle equipment which, as is well known,involves high power costs and frequent shut-downs for cleaning thenozzles to maintain them serviceable.

Some imperfectly atomized droplets of cleaning liquid will impinge onthe vanes 8 which act as bailies to prevent liquid from being thrown outof the entrance end of the duct A. Droplets which may be deposited uponthe vanes 8 are picked up by the entering air stream, and if notevaporated during passage through the chamber 9. are stopped by theillter I I through which they will descend and return to the bottom tankI 5. Although the filter II prevents the 'passage of substantially allentrained cleaning liquid droplets it is desirable to provide thesupplemental or second lter I3 which intercepts and returns to the tankany stray drops which may have worked through the filter I I.

In the illustrative embodiment of the invention the liquid throwing andatomizing equipment I comprises nine units each including a disc 23 andpan 24,deployed along the shaft I8. It is apparent, however, that thenumber of such units required will vary according to the size of theduct and the expanse of the filter pack II to be washed.

Completeand eillcient cleaning of air flowing through the duct Arequires the continuous delivery of great quantities of Water to the.chamber 9 and upon the lter II. By far the greater part of the' waterdrains back to the bottom tank I5 and is then reused, the cycle being acontinuous recirculation, Because of the large size of the tank I5the"1cleaning liquid supply is spreadout over a large area, which isconducive to precipitation of solid matter to the bottom of l the tank.Emcient precipitation of the solid particles is also enhanced byenclosing the bottom portions of the discs 23 within the pans 24 whichprevents the discs from maintaining the main body of cleaning liquid ina state of agitation, which would hold the solid particles insuspension. Thus' solid particles, once having been removed from the airstream and filter II, will not be picked up by the discs and thrown intothe chamber 9 or against the filter II. Only occasional or seasonalremoval of solid matter collected on the bottom of the tank is required.

Although most of. the cleaning liquid is kept in circulation, some of itis evaporated in cooling the air so that it is necessary to add make-upliquid in order to maintain the discs 23 bathed in liquid. As shown inFigures 2, 6'and 7, water or other cleaningv liquid may be drawn througha supply pipe or conduit 32 which leads through an injector valve 3 3 toa pipe or conduit 35 through which liquid is delivered to the tank I5.Figure 7 shows the valve in itsraised or open position but normally itis held on its seat by a spring 39 interposed between the valve head 31and a xed' spring seat 40. The valve is adapted 'to be opened by anelectrically operable device comprising a solenoid plunger 4I connectedto the upper end of a stem v38 and operable in a solenoid coil 42supported on a housing 43 which extends upwardly from the valve 33 andencloses the stem' 38 and spring 39.

As shown in Figure 4, a safety drain for preventing over'owing of thetank I5 comprises a pair of pipes 44 and 45 screwed into a fitting 46secured' to the lbottom of the tank I5. If the level of liquid in thetank I 5 rises above the top of the pipe 44 liquid will flow olf throughthe pipes 44 and 45 so as not to overiiow the tank. The tank may bedrained conveniently by merely unscrewing the pipe 44.

Apparatus embodying the invention preferably also includes an improvedarrangement of electrical equipment for controlling the operation of theblower, the atomizing` cleaning equipment II).` and the equipment foradding make-up cleaning liquid. Generally stated, a thermostat isresponsivelto the temperature of the air discharged by the apparatus forstarting and stopping the` blower B and the atomizing cleanser equipment6 III, and a humidostat is responsive to the humidity of the airdischarged by the apparatusy for controlling only the equipment III, Thearrangement is such that .when the thermostat calls for operation of theblower and the equipment IIJ these will operate providing the humidostatalso calls for operation of the equipment I0. If the thermostat callsfor operation and the humidostat does not call for operation, then onlythe blower will respond to the call of the thermostat.

A preferred arrangement of the electrical control equipment is showndiagrammatically in Figure 8 in which an electrical supply line isindicated at 53 as leading to a master cutout switch 54. One side of theswitch 54 leads through a conductor 55 to a thermostat 56 which ispositioned so as .to respond to the temperature of air discharged by theapparatus. The thermostat l56 is connected to a conductor 51 which leadsthrough another conductor 58 to one side of the blowermotor 3. The otherside of the motor 3 is connected to a conductor 59 which extends toelectrical switching means including two mercury switch tubes 69 and 6Imounted on an arm 62 carried by a rock shaft 63 journaled in a-sleeve 64as shown in Figure 6. The shaft 63 is provided with a crank arm 65connected to a stem 66 guided for vertical movement by a bracket 61secured to the inside of the tank I5. The lower end of the stem 66carries a float 68. When thereis a suillcient quantity of water in thetank I5 to insure bathing of the lower portions of the discs 23, themercury tube S I will be in the tipped position shown in Figure 8 sotha't current can flow through the tube 6I to a conductor 69 which leadsback to the other side of the master switch 54. Thus, when thethermostat responds to complete a circuit through the conductors 55 and51, the motor 3 will be operated to drive the blower. If, however, thelevel of liquid in the tank I5 is lowered to the extent that the discs23 will not be bathed, the oat 68 will descend to tip the switch tube 6Iand break the circuit between the conductors 59 and 69 which willprevent operation of the blower motor 3. Consequently the apparatuscannot operate to deliverair to the conditioned area whenthe atomizingcleaner is not conditioned to wash the air.

One side of the motor 28 which drives the discs 23 is connected toconductor 10 which in turn is connected to the conductor 59 in thecircuit of the blower motor 3, 'I'he other side of the disc motor 28 isconnected through a conductor 1I, a humidostat 12, and a conductor 'I3to the conductor 51. The humidostat 12 is located so as to be responsiveto the humidity of air delivered by the conditioning apparatus.

It will be apparent that the humidostat control is effective only uponthe atomizing cleanser motor 28 and not upon the blower motor 3. Thetipping of the switch tube 6l in response to failure to maintainsumcient liquid in the tank I5 to bathe the discs 2 3 also breaks thecircuit through the motor 23 so that the discs will not be rotatedunless they are bathed in sulcient liquid to insure proper cleaning ofthe air.-

The valve 33 controlling the addition of make.- up cleaning liquid isopened only when the liquid in the tank I5 descends to a predeterminedlevel somewhat higher than the level at which the entire apparatus isdisabled. -One side of the solenoid winding 42 is connected to theconductor 51 and the other side of the winding is connected through aconductor 14 to the mercury 7 switch tube 60 -which in turn is connectedthrough a conductor 15 to the motor circuit conductor 69. the tank Idescends to avpredle- If the liquid in I termined low level, the oat 83will move downwardly to tip the switch tube 60 until Vcontact is madebetween the conductors 14 and 15, thereby energizing the solenoidwinding 42 and opening the'valve 33. Whenpthe proper liquid level hasbeen restored in the/tank I5 the float 68 will rise to tip the switchtube -60 back to the position shown in Figure 8, thereby breaking thecircuit, deenergizing the solenoid winding and permitting the valve 33toclose. l

The cooperation of the component parts of thethrough the chamber 9 andcontacts the cleanin one part oi said duct to finely atomized liquidonstituting a fog'f'or mist in another part o'f said uct.

2. In air conditioning apparatus, a duct'l-e'quipment for moving airthroughv said duct: and

means for creating in said duct a diiused ,vol-v ume of liquid, saidmeans comprising a horizontal shaft; a plurality of spaced discs fixed`to said shaft,-at least one face of each of .said discs ybeing formedwith a concentric groove, means for holding a supply of liquid in suchposition that the lower portions of said discs and their grooves 'dipinto the liquid, and means for rotating said shaft and discs,saidgrocves respectively having outer annular walls ,substantiallyconstituting cylindrical surfaces wherebyliquid picked up in saidgrooves from said supply will gradually and ing liquid particles whichprogressively increase in size and coarseness of dispersion as thefilter I i is approached. Some of the solid particles entrained in theair are caught by liquid particles which drop back into the tank l5.Finally the air passes through the thoroughly wetted aeration pack orlter il which removes substantially all 0f the residual solid particlesand the cleaned air then passes on through the second filter pack i3 tothe blower chamber it.

Cooling of the air is accomplished by adiabatic saturation of liquid onthe vanes 8 and on the walls of the chamber 9, and the liquid which isdiffused or dispersed within the chamber 9. The final lowering of thetemperature, however, is accomplished by evaporation of themultitudinous films of liquid deposited on the myriad strands ii ofglass or the like in the lter il. vAny free moisture which may slip pastthe filter il will be trapped by the lter i3 from which it is returnedto the tank l5. Thus, only dust-free, clean, cool air withoutfreemoisture or clamminess is delivered to the conditioned area.

The apparatus disclosed by way of example embodies the invention in apreferred form, but it will be apparent that changes may be made in theconstruction of individual parts and their relative arrangement withoutdeparting from the invention as defined in the claims.

I claim:

l. In air conditioning apparatus, a duct; equipment for moving airthrough said duct; and means for creating in said duct a diffused volumeof liquid, said means comprising a disc having aI concentric groove inat least one of its faces, means providing a supply of liquid, meansmounting said disc to rotate with a portion thereof including saidgroove running through said liquid, and means for rotating said disc,said groove having an outer annular wall substantially constituting acylindrical surface whereby liquid picked up in said groove from saidsupply will gradually and progressively work its way laterally to thegrooved face of the disc thus retarding the discharging of part of thegroove-held liquid from the disc and causing the character of thediffused liquid to vary progressively from a forceful spray ofrelatively coarse separated particles progressively work its waylaterally to the faces of the discs thus retarding the discharging ofthe groove-held liquid from the discs and causing the character of thediffused liquid to vary progressively from a forceful spray ofrelatively coarse separated particles in one part of said duct to finelydivided atomized liquid constitutv ing a fog or mist in another part ofsaid duct.

3. In air conditioning apparatus, a duct; equipment for moving airthrough said duct; and means for creating in said duct adiffused volumeo f liquid, said means comprising a disc having a concentric groove inat least one of its faces, means mounting said disc to rotate about asubstantially horizontal axis, a pan closely embracing the lower portionef the disc with operating clearance between the pan and disc, means forsupplying liquid to said pan at a rate at least equal to the rate atwhich liquid is discharged from said pan by said disc so as to maintaina constant liquid level in the pan substantially above the bottom of thedisc, and means for rotating said disc, said groove having an outerannular wall substantially constituting a cylindrical surface wherebyliquid picked up in said groove from said supply will gradually andprogressively work its way laterally to the grooved face of the discthus retarding the discharging of part of the groove-held liquid fromthe disc and causing the character of the diiused liquid to varyprogressively from a forceful spray of relatively coarse separatedparticles in one part of said duct to finely atomized liquidconstituting a fog or mist in another part of said duct.

4. In air conditioning apparatus, a duct; equipment for moving airthrough said duct; and means for creating in said duct a diiiused volumeof liquid varying from relatively coarse separated liquid particles tonely atomized liquid constituting a fog or mist, said means comprising adisc having'a concentric groove in at least one of its faces, meansproviding a. supply of liquid, means mounting said disc to rotate with aportion thereof including said groove running through said liquid, adeector extending across and adjacent the periphery of said disc andterminating just beyond 'the point at which the disc passes out of saidliquid, and means for rotating said disc.

5. In air conditioning apparatus, a duct; equipment for moving airsubstantially horizontally through said duct; a lter pack havingsubstantially the properties of matted glass strands dising a fog ormist in said duct in advance of said lter pack, said means comprising ahorizontal shaft extending transversely to the flow of` air through saidduct and in advance of the lter pack, a plurality of substantiallyvertical discs xed to and deployedl along said shaft, each of said discshaving a concentric groove in at least one of its faces, means forapplying liquid to the discs, means for rotating said shaft, and deectormeans between said lter pack and said discs and close to said discs forconfining said stream of v relatively coarse separated liquid particlesto impinge on the upper portion of said lter pack, whereby the largeamount of liquid thrown on the upper portion of said lter pack willtrickle down through said pack to maintain it substantially uniformlywet.

6. In air conditioning apparatus, a duct; a blower for moving airthrough said duct; an electric motor for driving said blower; means forcreating in said duct a diffused volume of liquid varying fromrelatively coarse separated liquid particles to iinely atomized liquidconstituting a fog cr mist, said means comprising a plura-lityY of discsdeployed acrossthe ow of air through said duct and disposedsubstantially in vertical planes parallel to the direction of air ow,means for bathing the bottom portions of said discs with evaporativeiiuid, and an electric motor for rotating said discs; a thermostatresponsive to temperature of air discharged by said blower under controlof said thermostat and oper# ation of said discs under control of bothsaid thermostat and said humidostat; and means responsive to failure ofsaid disc bathing means to maintain the discs properly bathed in liquidfor'superseding the control effected by said ther-v 45 mostat and saidhumidostat and preventing operation of both said motors.

7. In air conditioning apparatus, 'a duct; a blower for moving airthrough said duct; an electric motor for driving said blower; means vforcreating in said duct a diffused volume of liquid varying fromrelatively coarse separated liquid ,particles to nely atomized liquidconstituting a fog or mist, said means comprising a plurality 10 ofdiscs deployed across the ow of air through said duct and disposedsubstantially in vertical planes parallel to the direction of air iiow,means including a tank underneath said discs for bathing the bottomportions of said discs with evaporative iiuid, an electrically operabledevice for introducing make-up evaporative iiuid to said tank, andanelectric motor for rotating said discs; a thermostat responsive totemperature of air discharged by said apparatus; a humidostat responsiveto humidity of the discharged air; means connecting said thermostat andsaid humidostat in controlling relation to said motors to eect operationof said blower under control oi' said thermostat and operation of saiddiscs under control of both said thermostat and said humidostat; andelectric switch means responsive to"= lowering of the liquid to a rstpredetermined level in said tank for effecting operation of said devicefor adding make-up evaporative liquid to said tank and responsive to'lowering of the liquid to a second predetermined level in said tank forsuperseding the control eected by said thermostat and said humidostatand preventing operation of both said motors.

THOMAS W. CARRAWAY.

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